This invention relates to structures for insulating a colder surface, area, or object from a warmer surface, area, or object and, more particularly, to an inflatable, insulating apparatus for applications such as in mattresses inflatable with air or another fluid.
It has long been a problem to insulate one surface, area, or object from another surface, area, or object where a temperature differential exists between the two. The problem is especially difficult for campers, hikers, and other outdoorsmen who must sleep outside, often during cold weather. Typically, such persons have utilized air mattresses which may be inflated for use, or foam pads of the closed or open-celled type which may be compressed, rolled, stored, and/or transported for such sleeping. At night, the ground temperature is usually much lower than that of the person's body; and the intermediate air mattress or foam pad may fail to sufficiently limit the transfer of heat from the sleeping person, with resulting discomfort.
In studying the problem, I have discovered that the discomfort caused when sleeping outside on cold ground with conventional mattresses results from the combined effects of thermal radiation from the body of the sleeping person and both free and forced convective heat transfer between the colder ground and the warmer body of the person through the intermediate mattress. Free convection results because of the fluid or air circulation between the opposite surfaces of the intermediate mattress which are at different temperatures. Forced convection arises from displacements of the fluid or air in the mattress due to various movements of the person thereon causing mixing of warmer and cooler air or fluid masses and the movement of air or fluid past mattress surfaces which are at a different temperature than the moving fluid.
In recognition of the above problems and the physical principles which result in those problems, the present invention is designed to overcome the above problems in inflatable air mattresses and in other applications where insulation is required.